On Tue, Sep 08, 2020 at 02:19:03PM +0000, Wei Liu wrote: > On Thu, Sep 03, 2020 at 11:05:37AM +0100, Paul Durrant wrote: > > From: Paul Durrant <pdurr...@amazon.com> > > > > The manpage for 'xl' documents that guest co-operation is required for a > > (non- > > forced) block-detach operation and that it may consequently fail. Currently, > > however, the implementation of generic device removal means that a time-out > > of a block-detach is being automatically re-tried with the force flag set > > rather than failing. This patch stops such behaviour. > > > > Signed-off-by: Paul Durrant <pdurr...@amazon.com> > > I'm two-minded here. > > On the one hand, special-casing VBD in libxl to conform to xl's > behaviour seems wrong to me. > > On the other hand, if we want to treat all devices the same in libxl, > libxl should drop its force-removal behaviour all together, and the > retry behaviour would need to be implemented in xl for all devices > excepts for VBD. This requires a bit of code churn and, more > importantly, changes how those device removal APIs behave. In the end > this effort may not worth it.
I would be worried about those changes, as we would likely have to also change libvirt or any other downstreams? > If we go with the patch here, we should document this special case on > libxl level somehow. > > Anthony and Ian, do you have any opinion on this? Maybe a new function should be introduced instead, that attempts to remove a device gracefully and fail otherwise? Then none of the current APIs would change, and xl could use this new function to handle VBD removal? Roger.
